The new version of the iPhone 5s is compatible with GSM networks, which include T-Mobile and AT&T. GSM networks are common throughout the globe, making the unlocked iPhone 5s a good option for users who travel abroad.

Because the device isn't locked to a network carrier, users don't have to sign up for carrier contracts. Instead, users can sign up for short-term plans and switch to other carriers whenever they want.

Normally, a 16 GB iPhone 5s retails for $199 but customers have to sign a two-year contract with the wireless service provider.

Apple's website currently says the device is available to ship within one to two weeks.